Printed circuit board assemblies (PCBAs) are used in numerous equipment including computers, telephones, major appliances, vehicles such as automobiles, trains, and planes, and toys, etc. The printed circuit boards (PCBs) are getting more crowded with items such as integrated circuits, resistors, heat sinks, and other components.
A series of processes is required to create the printed circuit board and add the components to the printed circuit board to create the completed printed circuit board assembly. One of the steps is the mounting of a plurality of components to the printed circuit board. Some of the components are computer chips. Computer chips are typically mounted by a solder joint, such as ball grid array, that functions as both the electrical connection and the mechanical connection.
It is not uncommon for printed circuit board assemblies to vary in temperature through out the life of the assembly. This heating and cooling results in thermal stress between the component such as the chip or silicon device and the underlying substrate, the printed circuit board.